In recent years, consumer digital still cameras and video cameras (hereinafter, will be referred to as “video movies”) have had unstable images displayed on screens thereof due to hand movement, and so on when capturing images. In order to solve the problem, digital still cameras and video movies including image blur correction devices have been developed or commercialized.
For example, there has been a method in which a variable angle prism is provided for the optical system of an image capture device, the movement of the image capture device is detected by an acceleration sensor, and according to the detection result, the variable angle prism is drivingly controlled to correct the motion of an image (e.g., see Patent Literature 1).
As another example, there has been proposed an imaging optical system having a variable power optical group or focusing group and a correction optical mechanism for decentering or tilting the optical axis of the imaging optical system (e.g., see Patent Literatures 2 and 3).
Further, for example, there has been known a method for correcting the motion of an image by moving a charge-coupled device (CCD) in a direction orthogonal to the optical axis (e.g., see Patent Literature 4).
In the above-described image blur correction devices, angular velocity sensors (gyro sensors) are mainly used which detect the shake of the image capture devices for the purpose of detecting the movement. Specifically, the angular velocity of movement of the image capture device is detected by the angular velocity sensor, integration is performed on the detected data to obtain the shake angle of the image capture device, and in accordance with the shake angle, the above-described variable angle prism is drivingly controlled. Further, the optical image of a subject is optically moved, so that the motion of the image is corrected.
In addition, there has been known a method for correcting the motion of the image by electronic processing.
For example, a captured image is temporarily stored in a memory, the motion vector of the entire image between continuous image frames is detected by a representative point matching method, and only a part of the image stored in the memory is read in accordance with the motion vector, so that the motion of the image is corrected (e.g., see Patent Literature 5).
Further, for example, there has been disclosed a technique for detecting the motion of a face of a subject in an image instead of the motion vector of the entire image to prevent the subject from being blurred (e.g., see Patent Literature 6). In this technique, a blur suppression unit is controlled in accordance with the motion of the subject (face), so that the relative position of the subject image in the picture frame can be fixed, as shown in FIG. 4 of Patent Literature 6. In other words, the motion of the subject image can be suppressed or the subject image can be followed to capture an image.